1. Field of the Invention
This invention relates to improved front and rear fascia of a motor vehicle having improved flexibility, wherein the improved elastomeric blend composition used in forming the fascia includes a neutralized sulfonated elastomeric polymer, a polyolefinic thermoplastic resin and a preferential plasticizer.
2. Description of the Prior Art
This invention relates to improved front and rear automotive fascia having an elastomeric-rich inner core and a thermoplastic-rich outer shell and the elastomeric compositions used in forming the automotive fascia include a neutralized sulfonated elastomeric polymer, a preferential plasticizer, and a polyolefinic thermoplastic resin, wherein the compositions can be readily extended with a critically selected class of fillers and oils.
Elastomeric polymers have been used for decorative and functional automotive parts such as trim or in energy-absorbing systems such as a bumper. Bumpers can be readily made by compression holding techniques; however, the formation of the complete front or rear fascia of an automobile is most economically done by an injection molding process. The injection molding of highly extended conventional elastomers, in general, requires extremely high pressure, thereby making it impossible to readily injection mold the complete front or rear automotive fascia. U.S. Pat. No. 3,915,928 is directed towards the formation of a conventional ethylene/propylene copolymer which could be injection molded to form a complete fascia. The compositions of U.S. Pat. No. 3,915,928 are glass filled EPDM terpolymers; however, these compositions have certain inherent disadvantages such as requiring heated molds for crosslinking resulting in long cycle times and in nonreprocessable products, thereby resulting in a high degree of scrap. When injection molded, they tend to form surface "trail" lines due to orientation of the glass fibers. Additionally, the use of glass fibers results in certain ecology problems resulting in increased cost of manufacture due to the necessary ecological control. The instant elastomeric blend compositions while providing improved physical properties such as flexibility, surface hardness, elongation and tensile strength at break also provide a material which is simpler to injection mold, readily reprocessable and one which avoids the ecology problems which are associated with glass filled elastomers.